Railway signaling.



S. C. HOFMANN.

RMLWAY SIGNAUNG.

APPLICATION FILED DEC. 30| 1913.

lPatented July l?, 1917'.

2 SHEETS-SHEET l.

s. C. HOFMANN.

RAILWAY SIGNALING.

APPLICATION FILED DEC.30.1913,.

Patenteduly 17, 1917.

2 SHEETS-SHEET 2.

HVETH i ne rarnnr arriba SEBASTIAN C. HOFMANN, OF OSAG CITY, MISSOURI, ASSIGNOR T 'II-IE UNION SWITCH & SIGNAL COMPANY, 0F S'WISSVALE, PENNSYLVANIA, A' CORPORATION OF PENN- SYLVANIA.

I RAILWAY SIGNALING.

Specification of Letters Patent.

Patented July i7, 1917.

To all whom it may concern:

Ie Vit known that I, SEBASTIAN C. Hor- MANN, a citizen of the United States, residing at Osage City, in the county of Cole and State of Missouri, have invented certain new and useful Improvements in Railway Signaling, of which the followingis a specification. f g

My invention relates to railway signaling, and particularly to signalingv for stretches ot single track over which traffic moves in both directions, such `for example, as stretches of single track betweenvpassing sidings.

I will describe certain icrms of signaling svstem. embodying my invention, and will then point out the novel features thereof in claims. Y i

In the accompanying' drawings,`Figure `1 is a diagrammatic vie-w. showiijig. a stretch ot single track havingapplied thereto'one 'Form of signaling system embodying my invention, and F ig. 2 is a view showing a ing. i.

Similar reference characters refer. tosimilar parts in both of the views.

.Referring iirst to Fig. l, A--B is a stretch ci single track between two passing sidings IC and I?, over which stretch trailic moves in both directions. Traliic through this stretch from cast to west is governed by signals S, S3 and S5 located at intervals through the stretch, and tratlic through the stretch .trom west to east is governed by other signals S2, S4 and S, located also at intervals through the stretch.

Iilach signal comprises a semaphore 2, biased by gravity or Otherwise to the danger position ot indication, an electric motor 5l, for moving the semaphore t0 another position lagainst its bias, and a holdingmagnet 4f for holding the semaphore in the position to which it has heen moved .by the motor. In my invention, the motor 3 is operatively connected with the semaphore to he driven as a. generator thereby while the semaphore is returning to danger position in response to its bias; Also in my-invention the armature of the' holding magnet 4 controls a contact 6 in suchmanner that when the magnet is energized this contact engages a t'ront contact point 7, and when the magnet is deiiinergiaed this contact G engages a back Contact point S. The

armature` of magnet 4 is operatively connected with the signal mechanism in a suit- `able manner, this connection being indicated ,diagrammatically in the drawings for the sakeA of simplicity.

In the drawings, I have shown the parts and D-fB, and as here shown a pair of op- Aposlng .signals 1s located near each )unction of adiacent sections, although I do not wish to be limited to this particular location of ythesignals. Each section is provided with one or more track circuits including track relays for the control of the signals. As here shown each section is divided by insulated joints 5S into two sub-sections, and each sub-section is provided with a separate track circuit. For example, section A-C is divided into .two sub-sections A-Q Q-C. Each track circuit comprises the rails ofthe subsection, a battery l), and a track relay; the track relays are designated by the reference character 'Ilwith the same exponent as that ot-the adjacent signal which. governs traflic through the corresponding sub-section.

F or each signal I provide a signal relay 'for the control` thereof, which relays are designated in the dra-wing by the reference character R with an exponent corresponding to lthe exponent of the signal which the relay controls. Each signal is provided with a circuit which is controlled by the corresponding signal relay. For example, the circuit for signal Sis from battery IO through wires ll` l2, I3, and 27, contact 28 of relay R,- wire 29, holding magnet 4, wire 30 and common wire 0 to battery l0.V This circuit lwhen closed energizes magnet a thereby closing contact @-7 of this magnet so-that the signal motor 3 is then energized by a, branch .of the sign al circuit, which branch is from. wire 29 through circuit controller 5 wire 3l contact 7 6 wire 32 moa 7 'i 7 opens when the signal reaches clear position `so that the moto-r 3 thenstops. Each of the Vother signals is provided with a circuit similar to that for signal S3;

Eachsignal relay (except relays Re and R5) is controlled by both track relays for the sec-.

tion through which the corresponding sigv.AnalV governs traliic, andY also by the signal relay for the ysignal next in advance governing traffic in lthe same direction.y v,For example, relay R,'\vhi`ch controls S'gl'al VS', is provided withgth'e following jcircuitl-lfroin battery 10, through `wires 11,y 12, 13 'and 14, contact 15 ol relay R3, wij-res 16 and 17, 'colitact 18 of track relay T6, wire 19, 'contact 20er track relay fT, wire 21, jsigiial relay R, lwires Q2 and 23, and common wire '0 to bz'tttery 10,. ,The Vcircuits for 'signal 'relays R3, R4, and R2 are similar to that just traced for y'relay R. The circuits A for signal relays R jand Rare similar to that just traced fior relay R except that they arejc'ontrolle'd lonly bythe 'track relays for sections D-B danger indication.

and respectively, there being, in the i torni 'of signaling here shown, 'no .s'ignalrellays to control these circuits. K i l It will be seen thatlas thus far described,

[each signal frelay controls lthe' 'signal relay for'the signal next fin thev rear governing trallic in the same direction. Hence, as 'a train enters the stretch from either end, all

the signals governing traliic through V'the stretchin the direction opposite tothat in which Vthe train is moving will change to Means are provided, however, for each signal relay for .at times lrendering` it ineffective to control the signal relay next in the rear, sol that as ia train proceeds through the stretch 'certainsignals Y 4e f position thereby permitting a following in the rear of the train may change to 'clear "as that of the corresponding signal relay.

For example, the branch around contact 15 of signal relay Rgis from wire 11 through wire 24, contact of vauxiliary relay 'X2 wireQS, to wire 17. It will beseen thafteach auxiliary relay, when energized, closes -the branch around the contact of the correspond- Ving` signal relayand thus renders such signal relay ineffective to control the signal relay for the signal next inthe rear. No auxiliary y l relays are provided for signal relays R and R2, lbecause these relays vdo not'control other signal relays in the illustrated embodiment offmy invention.

ln the einbodimentof my invention shown in Fig. 1,"each auxiliary relay X comprises 'two windings, viz., a pick-up winding 34 and Lasagne' a holding winding 35. The pick-up winding 34 of each of these relays is arranged to be energized by current generated by the motor 3 of the corresponding signal while the signal is moving toward the danger yposition, but only when such movement of the signal is caused by a train entering the section through which the signal governs trafc. For example, the circuit for the pick-up winding 34 of relay X3 is Jfrom the upper brush of motor 3 of signal S3 through wire 32, contact 6, back contact point S, wire 36, contact 37 of track relay T3, back contact 'point 40, wire 38, .pick-up winding 3,4-, wires 1.9, 30 and 33 to lower brush of motor 3. lt

will be seen that this circuit is closed only when magnet 4 is dener'gized and track rclay T3 is open, hence the pick-up windin g 3l is energized only when a westbound trainenters section D-C. The current iowing iii this circuit also retards the ymovement ot the 'signal and thereby prevents shock to the signal mechanism when the danger position is reached. When signal S3 moves to dau- 'ger position fromany other cause, as, for f example, when its controlling relay R is opened by an eastbound train entering stretch A-B, track relay T is closed, so :that the circuit vfor motor 3 is then from the 'upper Ibrush through wire 32, contact 0 8, wire 3G, Contact 37 of relay T, iront `contact point 411, resistance 42, wires and to lower brush of motor 3. The current gcnerated by the motor and flowing in this circuit also serves to retard the movement of the signal mechanism .an d to thereby prevent shock when the 'danger position is reached, the speed of such movement being determined by the value of resistance 42.

The holding winding '35 of each auxiliary relay is 'provided with a circuit which in- .clu'des ya front contact of the relay itself and a lback Contact of the corresponding signal relay. For example, the circuit 'for the holding winding '35 of relay X3 is from battery 1'0 through wires 1l, '12, and 43, vback contact 44 of signal relay R, wire 45, coutact 46 'of relay X3, wire 47, holding winding 35, wire 48 and cominon wire 0 to battery i0.

jPreferably the pick-up winding 34 aud the holding winding of each auxiliary relay are so arranged relative to each other that the ilux in the relay core produced by the piek-up 'current in winding 34 is in the same direction as the ilux produced by the holding current in winding 35.

The circuits for the pick-up and holding windings of auxiliary relays X, X4 and X are'similar to those just traced for relay X. Since the motor 3 of signal S is not employed to energize an auxiliary relay, this motor is Aprovided with a ietarding circuit which is not controlled by a track relay, and which is from the upper brush of the motor through wire 32, contact 6-8, wire 49, re-` sistance 42, wires 30 and 33 to lower brush of the motor. It is understood that the motor for signal S2 is provided with a similar retarding circuit.

The operation of the apparatus during the passage of a westbound car or train through the stretch is as follows-as the car or train enters section BHD, it opens track relay T, thereby opening at contact 20 the circuit for signal relay R', which relay in turn opens at contact 51 the circuit for signal S so that this signal then moves to danger. The opening of track relay T also opens at contact 50 the circuit for signal relay R, which latter relay opens at contact 52 the circuit for signal S so that this signal also moves to danger position. The opening of signal relay R6 opensV at contact 53 the circuit for signal relay R4, which latter causes signal S4 to move to danger; relay Rt in turn'opens the circuit for relay R2 thereby causing signal S2 to move to danger position. It will be seen, therefore, that all of the eastbound signals are now in danger position thereby prohibiting the passage of an eastbound car or train through the stretch A+B.

As the car or train passes out of subsection B56 and enters sub-section 56-1), it opens track -relay TG and permits track relay T to close, but this has no effect on the signals, because `these two track relays control the same circuits.

As the car or train enters the sub-section D-57, it opens track relay T3, which latter opens at contact 54 the circuit for signal relay R3 thereby opening at contact 28 the circuit for the holding magnet 4 of signal S3 so that this signal then moves to danger position. Track relay T3 being open, the circuit for the pick-up winding34 of auxiliary relay X is closed so that this winding is energized by the current generated by motor 3 of signal S3 while this signal is moving toward danger position, and relay X3 is thereby closed. Inasmuch as signal relay R3 is open, the circuit for the holding winding 35 of relay X3 is closed at contact 44, so that this relay continues to be energized after signal S3 has reached the danger position. Signal relay R3 is now ineffective to control signal relay R, so that as soon as the rear end of the car or train has left section B-D signal relay R closes, thereby causing signal S to change to clear position so that a following westbound car or train maythen enter the stretch A-B.

As the car or train passes out of the first sub-section to section D-C and enters the second sub-section, it opens track relay T4 and permits track relay Tg to close, but this change has no effect on the signals because the circuits controlled by these relays are the same. I

The operation of the apparatus during the passage of the car or train through the remainder of the stretch is the same Vas that thus far described, hence it need not be traced further.

The operation of the apparatus during the passage of an eastbound car or train through the stretch is the same as that just described for the passage of a westbound car or train.

One important feature ofthe apparatus shown in Fig; 1 is that after an auxiliary relay is once closed there is no interval during which it is denergized, hence these relays need not be slow-acting; in other words, the pick-up `and holding circuits for each auxiliary relay are prepared for their functions before current is applied to them, and the holding circuit is not afterward changed until time for the relay to be deenergized. Another important feature is that each auxiliary relay is not closed until the proper time for it to perform its function. Still another feature is that an auxiliary relay which allows a signal to be cleared can not be closed until the next signalin advance moves to danger, because it is the movement of this latter signal which causes the relay to close. v

Referring now to Fig. 2, the apparatus here shown is the same as that shown in Fig.` 1, except that the auxiliary relays, which I have here designated Y, each comprise only a single winding, which winding is employed both for pick-up and holding purposes. For the sake of simplicity I have in Fig. 2 shown only the signals S3 and S6, and the apparatus pertaining thereto. VThe circuits shown in Fig. -2 are the same as those shown in Fig. 1, except that in Fig. 2 the holding circuit for each auxiliary relay is as follows: from battery 10 through wires 11, 12 and 43, contact 44 of relay R3, wire 45, resistance 55, contact 46 of relay YS, wire 47, winding of relay Ya, wires 19, 30 and ycommon wire 0 tobattery 10.

It will be noted that after relay is closed, a portion, of the current from battery 1() will flow through motor 3, the branch in which this portion flows being from wire 47 through wire 38, contact 37, wire 36, contact 6, wire 32, motor 3, wires 33 and'30 to battery 10. lf this portion of the current were of suflicient value it would retard the movement of the signal toward danger and might even stop the signal and drive it back to clear position. The purpose of the resistance 55 is to limit the current from battery 10 to such value that the portion whichflows through motor 3 will not inter` fere with the movement of the signal toward danger.

Vith the structure shown in Fig. 2, the pick-up and the holding currents in each auxiliary relay Y are in opposite directions. The pick-up current, while it exists, is

rstronger than the lholding current, hence as the former dies away there is a reversal ofthedirection of current in the relay winding.' IIence the auxiliary relays must be of a type which vwill not open vwhen the vdirection of current in its Winding reverses.

Relays of this type are well known in the art.` These .relays may, for example, cornprise three poles two only of which are provided with windings, the windings having t different inductances.

i Although I have yherein shown land -described only two forms of signalingsystem embodying my invention, it is understood that various changes land modifications may be made therein within the scope oft-he ap- 'A pended claims, without .departing from the spirit and iscopeoif my invent-ion.

Having thus described my invention., what i claim is: V Y

j 1. In combination, a stretch of railway track, ksignals located at intervals through the stretch for governing trailic in one ,di-

rection, and other signals located at intervals' throiiglithe stretch for governing trai'- Y fic in the other direction; each signal coinprising an electric motor' arranged to be driven as a Vgenerator by the signal while the latter is moving toward danger, .a signal re- 30 layv vfor, controlling each signal, track circuits ;tor the stretch including track relays Ifor controlling saidisignal relays, means for relay forv'the signal next in advance vgoverning traii'ic 'in (the saine direction, an auxiliary ielay for each sign-al for vrendering the corresponding signal relay ineffective to conltrol the signal ,relay Vfor the signalnext in tlierean and means orgenergizingeach of said auxiliary relays fby current generated lby Athe .motor 'of' the corresponding signal while the latter is :moving toward danger.

v 2. In combi-nation, a stretch of railway track, signals located -a't intervals through the stretch vifor 'governi-ing vtraiiic in one direc- `tion, and kot-her signals located at Aintervals Jthrough the stretch for governing traffic in the other direction; each signal lcomprising anelectric motor arranged to be driven as a -generator bythe signal while ythe latter is movin toward danger a siOrnal rela -for 'controlling each signalftrack circuits for `the stretch including track relays for controlling said signal relays, means :for con- 'tio'llingeach signal relay by the signal relay @for the signal next in advance :governing 'traffic in the saine direction, 'and means for reach signal and controlledby the ycurrent generatedib'y the signal vmotor while the signalis moving*toward'danger for rendering the corresponding signal relay ineiiective to a control the sig-nal relay lfor thefsignal next I trac'k, signals located-at intervals through in the rear. Y Y y VV3.' In combination, a lstretch oli' railway the stretch Jfor governing traliic in one direction, and other signals located at intervals vfor governing ti'aliic in the other direction,

vby current generated by the signal motor while the signal is moving toward danger for rendering the .corresponding signal-controlling ineans ineltective to control the nal-controlling means for the signal next in the rear.

4. In combination, a stretch of railway track, signals located at intervals through the stretch `toi' governing trailic in one direction, and other signals located at .intervlic -in the other direct-ion; each signal coinpiising van electric motor arranged to be driven as a generator by the signal while .the latter is moving toward danger, a signal relay for controlling ,each signal, ineans for controlling each signal relay by the signal relay forthe signal next in advance governing traliicin the saine direction, an auxiliary r relay for each signal fOr rendering the roi responding signal relay ineilective to ,control the signal relay for the signal next inthe rear, a `pick-.up vand a `holding circuit for each auxiliary relay, .each pick-up circuit including the motor of lthe correspoinling signal and each holding circuit including a front contact of the auxiliary relay itself, and track circuits for the stretch incl riding track relays for the control oit the signal relays and .of the circuits for the auxiliary relays;

5. In combination, a stretch of ,railway track divided into a plurality of sections, a pair ot' opposing Vsignals located substantially at each junction `of adjacent sections for governing traliic in opposite directions, each signal comprising an electric motor arranged to be driven as a generator hy the signal while the latter is moving toward danger, a signal relay tor the control ot `each signal, track-circuits for the sections,

each :including a track .relay -ior controlling the signal relay for each signal governing traflic through the section; means 'orcontrolling each signal relay by the signal relay for the signal next in advance governing tra-flic inthe saine direction, an auxiliary relay for each signal adapted when energiZed to render the corresponding signal re- `layineffective to control the signal relay for the signal next in the rear, a pick-up and a holding circuit for each auxiliary relay, each pick-up circuit including the motor of the corresponding signal and a back contact of a track relay for the section through which the last-mentioned signal governs tra'tlic, and each holding circuit including a front contact of the auxiliary relay and a back contact of the corresponding signal relay and a source of current.

6. ln combination, a stretch oi railway track, signals located at intervals through the stretch for governing traiiic in one direction, and other signals located at inter'- vals for governing tratlic in the other direction, each signal comprising an electric motor for moving it toward clear position and said motor being operatively connected with the signal to be driven thereby as a generator when the signal is returning toward danger position, a signal relay for each signal, means `for each signal and controlled by the corresponding signal relay for supplying current to the signal to drive it to the clear position and to hold it in clear position, means for controlling each signal relay by the signal relay for the signal next in advance governing traffic in the same direction, an auxiliary relay for each signal for rendering the corresponding signal relay ineiiiective to control the signal relay for the signal next in the rear, means for energizing each auxiliary relay by eurrent generated by the motor of the corresponding signal while the signal is moving toward danger, and track circuits for the stretch including track relays for controlling said signal relays and said auxiliary relays.

7. In combination, a stretch of railway track, signals located at intervals through the stretch for governing trali'ic in one direction, and other signals located at intervals through the stretch for governing traiiic in the other direction; each signal comprising an electric motor arranged to be driven as a generator by the signal while the latter is moving toward danger, a signal relay for controlling each signal, means for controlling each signal relay by the signal relay for the signal next in advance governing traliic in the same direction, an auxiliary relay for each signal for rendering the corresponding signal relay ineffective to control the signal relay for the signal next in the rear, each auxiliary relay Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents comprising a pick-up winding and .a holding winding, means for energizing the pickup winding of each relay by current generated by the motor of the corresponding signal while the latter is moving toward danger, a stick circuit for the holding winding of each auxiliary relay, and track circuits including track relays for controlling said signal relays and said auxiliary relays.

S. ln combination, a stretch of railway track, signals located at intervals through the stretch for governing traliic in one direction, and other' signals located at intervals :tor governing traic in the other direction, each signal comprising an electric motor arranged to be driven as a generator' by the signal while the latter is moving toward danger, means controlled by a train in the stretch for causing all of the signals for the stretch to indicate danger, and means controlled by the current generated by the -signal motors for rendering said means ineffective to hold at danger the signals in the rear of the train governing traffic in the direction of movement of the train after the train has passed out of the portion of the stretch governed by such signals.

9. In combination, a stretch of railway track, signals located at intervals through the stretch for governing trailic in one direction, each signal comprising an electric motor arranged to be driven as a generator lby the signal while the latter is moving toward danger, a signal relay for controlling each signal, track circuits for the stretch including track relays for controlling said signal relays, means for controlling each signal relay by the signal relay for the signal next in advance, an auxiliary relay for each signal for rendering the correspondingsignal relay ineffective to control the signal relay for the signal next in the rear, and means for energizing each auxiliary relay by current generated 'by the motor of the corresponding signal while the latter is moving toward danger.

In testimony whereof I aiiix my signature in pres ance of two witnesses,

SEBAS/TIAN C. HOFMANN.

Witnesses:

O. L. MOORE, J. W. RINER.

Washington, D. G. 

